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By AES
#1198843
PART 1:

This piece is supposed to compliment my earlier long post about files and filing. Like the previous (now a sticky - "fame at last!" - thanks CHJ), it's very much aimed at the hobby woodworker faced with doing just a bit of metal bashing now and then.

As I was lucky enough to have a "proper" apprenticeship, when we learnt a lot of stuff like metal cutting, here goes.

This is mainly what I was taught, plus some bits & pieces of experience picked up along the way. But just because "I" say "this is the way", or "I was taught to do this in a that way", if you have your own other way of doing things which work successfully for you, then the best of luck. There are a few (and only a VERY few) "real rights and wrongs" here - as so often in life. But for those new to the whole business of metal working, here's a good starter for you.

SUMMARY:

First, to encapsulate what's discussed below, and for those who can't be bothered with long and complicated discussions, here's my own version of the "Metal Cutting by Hand Top 10" (top 6 actually):

1st: Full size hacksaw with bi-metal/all-hard blades (plus PERHAPS also a diamond/carbide coated and/or a power
hacksaw blade);

2nd: IF available, abrasive cut-off discs ("DREMEL"- sized drill or Angle Grinder, to suit job size & availability),

3rd: IF available, "GOSCUT" tool - for sheet metal;

4th: IF available, electric drill "NIBBLER" accessory - for sheet metal;

5th: Powered scroll/fret saw - sheet metal (again!);

6th: Jigsaw (if no GOSCUT or NIBBLER available) - sheet metal, yet again!

As there are only two basic types of hacksaw frame we'll start off there.

DETAIL 1. JUNIOR (or "MINI") HACKSAWS:

Here are three slightly different variants on the basic theme:

Photo 1 HS
1 HS-C.jpg


The most common and cheapest type (top in picture) consists of a "sprung" frame with an integral "bent-up" handle. Not the most comfortable to hold, but "it'll do". The centre example is also quite common but a little more "refined". It has a male threaded boss at the back of the frame onto which a metal heavy-duty craft knife handle is screwed. The lower example is more posh, having a cast frame handle with threaded blade tensioner built in. The most comfortable in my opinion.

All are designed to take 6 inch long blades, and as far as I've seen, this Imperial measurement is also valid in Metric countries.

Junior hacksaw blades all have a small steel pin set horizontally through the blade at each end. These fit into a slot in each end of the frame. Again as far as I've seen, junior hack saw blades are not often branded, and seem to come in "no name" packs of 10 or so which are marked either Coarse or Fine. In my own stock the fine blades seem to be about 30 TPI, the coarse about 18 TPI.

The steel used for these blades is pretty soft for a cutting tool. This means that A), they tend to wear out quickly, and B), unless you take steps to increase blade tension it's pretty difficult to cut a truly straight line.

In the case of the two frames shown at the top and centre of the photo, tensioning the blade means gripping the frame in the vice (without blade) then giving it a bend/tweak until you can still (just) get the blade into the frame as you now fit a blade by flexing the frame against the bench. The more complicated frame shown at the bottom has the benefit of giving more scope for tensioning by means of a screw thread and thumb wheel. To increase available tension on what generally seems to be a pretty short thread, my method is to place washer/s of differing thickness between the thumb wheel and the frame because as bought, the available adjustment length isn't really sufficient I find. Care with tensioning this way is needed though, as on my own example ("Little Marvel" brand) the cast handle looks a bit weak in places and I guess such handles would easily bend or more likely break if over-tensioned.

As the teeth are small, junior hacksaw blades do not have set on each individual tooth. Instead they're "wavy set", meaning that the first tooth has no set; then the next 3 or 4 teeth have a set which increases to the maximum on one side; then the next 3 or 4 teeth return to zero set; then the next 3 or 4 are increasingly set in steps to maximum on the other side; followed by a return to zero set - and so on and so on. I hope that's clear in the photo below. It's also worth noting that blades for full size hacksaws (see later on) and a few other metal cutting blades, such as those for jigsaws (also see later on), are often also "wavy set", just like junior hacksaw blades.

Photo 2 HS
2 HS-C.jpg


Like all other hacksaw blades, junior blades should be installed so that they cut on the forward stroke. I've seen no help with getting this right with junior blades, unlike the big blades which generally have a different paint colour or shading of some sort at the forward blade end to make sure you get it right. Here, you just have to eyeball it.

Diag 3 HS
3 HS-C.jpg


Due to the above-mentioned softness and limited tension, junior hack saws can't really be considered as precision tools, but they are often handy for small/delicate jobs in the shop, and I imagine would be useful for site workers to have in the tool bag on a "just in case" basis. I also find mine quite useful for clearing damaged (or making new) slotted heads on grub screws, etc.

The fine junior blades are also quite useful for rough-cutting smaller/thinner plastic items such as small electrical conduit and ducting.

DETAIL 2. HACKSAWS:

Photo 4 HS
4 HS-C.jpg


Again there are several variations on the basic theme. A couple of my own are shown, and these are the more modern types, with a tubular steel frame with a cast metal (or moulded plastic) closed-grip handle. Earlier versions are still around, and these tend to have flat steel strip frames and file-type wooden handles which screw onto a boss at the back of the frame. This brings the handle into line with the blade. Both are perfectly serviceable, and as with just about all other tools, we all develop our own preferences. Personally I like the type shown above.

Some hacksaw frames are adjustable in length, being capable of taking both "standard" 10 inch and 12 inch blades. The adjustable length types tend to be the older ones (with the in-line handle), but I haven't seen any 10 inch hacksaw blades on sale for many a long year. I've no idea if they're even still made, but we can say that hacksaw blades come (came?) in either 10 inch (if you can find them) or 12 inch lengths. This Imperial standard also seems to be valid in Metric countries.

Just like 10 inch blades, it used to be possible to buy "Coarse" blades, meaning 14 TPI. But again I haven't seen any 14 TPI blades on sale for a long time. That's a pity, because for heavy cutting in thick stock these really are very good tools. But I still have a couple of old stock 12 inch long X 14 TPI blades which I now only use when really necessary.

Apart from 14 TPI blades, the three standard TPIs are 18, 24, & 32 TPI, although in many of the more DIY-oriented stores, only 24 TPI seem commonly available. A pity that, because as we shall see, having all three TPIs to hand is very useful, and saves a LOT of wasted energy - something I'm ALL in favour of whenever possible!

Photo 5 HS
5 HS-C.jpg


Apart from two length/s and three (or possibly four) different TPIs, there are three different types of blade available - "cheapos" which may or may not have had some type of hardening process, but which are anyway made of pretty soft steel (i.e. they wear out quickly unless used only on soft metals and plastics). And these blades are also rather flexible, which may seem an advantage, but that definitely isn't so once you've got the hack sawing knack. Read on!

Then there are properly hardened and tempered tool steel blades. In the interests of long life and cutting ability, these are pretty hard, and cut very well indeed when used properly, but they do tend to shatter if flexed or bent off line, often by not very much (leaving bits of blade to go pinging about all over the place - DAMHIKT)! A favourite old dodge was to grind these into very handy general purpose knives (with suitable handle!) once finally worn out.

And a relatively new addition to the armoury is the diamond-coated blade, also shown at the top of Photo 5. These are generally made from a "soft-ish" steel backing blade which is diamond or hard metal (carbide, etc) impregnated along the cutting edge, producing a somewhat thicker kerf than conventional blades. These are useful for getting out of trouble when faced with cutting really hard metals and are handy to have as a back up, but as we'll see later, IMO there are an even better options for cutting really hard metals.

Finally, and much more common these days, come "bi-metal" blades. These consist of a very narrow flat wire strip of tool steel, suitably tooth-cut and hardened and tempered. This wire is then "vacuum-beam" welded onto a much softer steel backing strip to make up the full approx 1/2 inch (12 mm) width of the standard blade.

These are the 3 blue and orange blades shown in Photo 5 above. Below (Photo 6) I've tried to show the very thin line of weld just above the root of the teeth. To make it visible I had to take a fine wire brush to the colour on a partly used blade - look for the fine grey-ish line just above the gullets of the teeth. This is where the thin strip of tool steel is joined to the much softer backing strip. That welding process is very interesting incidentally - long rolls of flat strip of each type are held in a special jig, then fed into a vacuum chamber (to eliminate weld impurities) where they're welded together by a computer-controlled electron beam, resulting in an apparently one-piece blade. All such welds I've seen are impeccable.

Photo 6 HS
6 HS-C.jpg
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Bi-metal blades are a good all round compromise, because unlike the all hard blades mentioned above, which really did give problems with shattering almost immediately as they strayed off the intended vertical cut line, you can literally twist bi-metal blades about all over the place with very small risk of blade breakage. I've seen the odd bi-metal blade with just a few teeth broken off (usually somewhere in the middle!) but leaving the rest of the blade "more or less" intact and still usable. They are pretty good on tough metals like various grades of stainless steel.

The basic bi-metal idea is so good that nowadays hole saws are often available in bi-metal configuration, amongst other applications. See later.

Like most compromises however, there's a down side to bi-metal hacksaw blades. Even with a hacksaw frame which allows plenty of scope for blade tensioning, bi-metal blades tend to wander off the straight and narrow all on their own - simply because they're so flexible. The resulting cuts are less accurate than could be achieved with a properly used all-hard blade.

My fix for this problem (but only a partial fix I'm afraid) is to add washers of suitable thickness to allow the blade to be tightened as much as the frame will allow - like the junior frames mentioned above, I find that as standard, the adjusting screw thread is a bit too short to allow maximum tension, especially for bi-metal blades. Even so, I still find it necessary to cut a little further away from the line than would be necessary with an all hard blade because I find bi-metal blades still tend to wander off line a bit - all of their own volition (he says innocently)!

Once you get reasonably comfortable with wielding the hacksaw properly though, the all hard blades are the ones to look out for, but around these parts anyway, bi-metal blades seem to have just about taken over in most shops, even in "serious" tool stores. I think you may have to look quite hard for all hard blades but admit that after a 25+ year absence from UK I'm not exactly up to date on what is/is not freely available these days.

DETAIL 3. HACKSAW BLADE SELECTION:

OK, having already established that 12 inch bi-metal blades are what you're most likely to come across, what about choice? As said, the really coarse 14 TPI blades seem to be very rare, leaving just the 18, 24, and 32 TPI blades to be found. But at first try you'll most likely often find only 24 TPI blades in the shops.

That's "OK-ish", because 24 TPI is obviously a reasonable compromise between 32 and 18 TPI. But if you've got any more work than just the very occasional bit of metal to cut, it's definitely worth making an effort to find 18 and 32 TPI blades as well.

One reason is the well-known "3 teeth in contact at all times" rule. If you've got some thin sheet material to cut, a 32 TPI blade is the obvious choice - you'll find it VERY difficult to cut thin sheet with a 24 TPI blade because it will tend to jam with the blade stuck fast in the job by the gullet of just one tooth.

Equally, if cutting, for example, a two inch thick piece of steel, it's going to take you all day with a 24 TPI blade, however sharp it is. An 18 TPI (or even better, a 14 TPI blade if you can find one) will be MUCH quicker, and you'll use a LOT less energy.

So in my own shop I have three hacksaw frames, one for each common blade TPI. A little OTT perhaps, but handy all the same - a bit like having three drill-drivers on a job, one chucked with a pilot hole drill, one with a countersink bit, and the last with a screwdriver bit.

But back to blade selection - in short, material thickness more than any other consideration should be your guide when selecting which TPI blade to use.

Once you've mastered hack sawing though (and it's NOT all that hard really - it simply needs some thoughtful practice), then IMO anyway, the all hard blades really are the bee's knees and are my own weapon of first choice nearly every time.

I've added a small list of the known good blade manufacturers at the end, because in the case of hacksaw blades I've always found that buying a "cheapo, no name" blade definitely is a complete waste of the hard-earned!

DETAIL 4. STARTING A CUT:

Here I'll pinch directly from my earlier piece, "Files & Filing":

At secondary school (which was the only formal wood work teaching I've had), I was taught that when cutting timber it's important to start the cut by placing the thumb just to the waste side of the chosen mark, then draw the saw backwards a few times (I'm assuming a conventional wood saw here, not a Japanese saw or any other which cuts on the back stroke). This makes a small vee in the job and ensures that the saw doesn't bounce out of the proper position as you start the real, forward stroke sawing. I hope that's the right procedure for wood!

But I've seen many beginners attempting exactly the same procedure when starting to cut a piece of metal with a hacksaw. Unfortunately, this is usually doomed to failure as the hacksaw will usually just bounce around all over the place on the top surface of the job. Not at all what we want for the start of a cut which is supposed to be in the right place!

Diag 7 HS (FF 28)
7 FF28-C.jpg


The following method will work EVERY time, WITHOUT fail. Use a short smooth triangular or half-round file to make a small vee similar on the top rear of the job. It's much easier to keep a file in the correct position for a few strokes than trying to do it with the hacksaw. But do make sure to keep the flat surface of the file as close to the mark as you dare (!!), and also, keep the flat surface of the file as vertical as you possibly can, leaving the half-round or the other two sides of the triangle to cut into the waste metal. See diagram 7 above.

DETAIL 5. HACK SAWING TECHNIQUE:

NOW we get to it! Hack sawing is very much like filing - so much so that you can almost consider a hacksaw blade as a file with just a single line of teeth! And just like I said in my filing piece, it's common to see folks "attacking" a piece of metal with a hack saw by using VERY short strokes and just "smashing" backwards and forwards at breath-taking speed - even on the non-speeded up YouTube video sequences!

I guess that's natural enough. Someone with little or no experience of cutting metal thinks "metal is hard, I don't really want to do this, but it must be done, so let's get it over and done with as soon as possible, cut, cut, cut," - pause to wipe sweat from brow and eyes - followed by even more frantic "cut, cut, cut, cutting"!

Now I'm not suggesting that hack sawing is great fun, but one thing I definitely can assure you, when taken at a SLOW and STEADY pace, using at least 75 to 85% of the full length of the blade for each stroke, you will not only cut the job MUCH quicker but you will also save a LOT of energy - not to mention no longer suffering from blades with teeth completely worn away in the middle and virtually untouched at each end!

Hacksaws cut on the forward stroke, as shown in Diagram 3 above, so the differently coloured/shaded part of the blade usually found on most hacksaw blades goes at the front of the frame.

Just like filing, your stance is very important. For right-handers, the preferred position is with your right foot in front of the vice and slightly to the right of the vice centre line, and with your left foot about one normal pace forward and slightly to the left of the vice centre line.

Set the work up vertically or horizontally in the vice, as appropriate - use a small spirit level or square if necessary. This gives you the best chance of making an accurate cut. And don't set the job too high up in the jaws either. Too high leads to work piece vibration and chatter and that only increases the cutting effort needed AND significantly reduces cut accuracy.

Start the cut with a file, as described above, and then place the saw blade in the file-cut vee with the handle end of the saw as far back as reasonably comfortable from the vice front. MAYBE the saw is held with the front SLIGHTLY lower than the rear - whatever you find most comfortable. Now make a forward stroke with medium downwards pressure at slow speed until the handle has almost contacted the front face of the vice. Now REDUCE the downwards pressure to ALMOST nothing, then draw the saw back towards you, keeping it in LIGHT contact with the job until you're back in the original start position. Then repeat.

If you've previously tried the frantic "cut, cut, cut" method that I caricatured above (I bet you have!), now compare how well and how quickly the saw has cut using this "approved method" - and after just a few (almost) painless strokes! Sometimes these old blokes (like the instructor who taught me) were not so soft after all it seems.

Of course this all takes much longer to write (and to read!) than to actually perform, so I hope the photos below plus a bit of practice will help you develop the basic method. As with just about everything else, "practice makes perfect". But I think you'll find it's easier than learning to file accurately - AND sawing correctly will help you improve your filing technique too. So overall, not bad really, as you get to be a winner all ways round!

Photo 8 HS
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Photo 9 HS
9 HS-C.jpg
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Unlike filing, it's not necessary to worry too much about the natural up and down rocking motion that you will probably automatically develop while making your to and fro hacksaw cuts - in fact, provided you don't allow it to become excessive, and provided almost the full length of the blade is being used on every stroke, a little up and down rocking can usually help the blade to bite better.

But this time, just like when sawing timber, it IS necessary to eyeball the cut (usually it's best done with the job still in the vice, unlike when filing). This "shufti-checking" means looking from in front and even from behind the job, and of course, from above. This is to ensure the cut is proceeding correctly against the pre-prepared vertical and/or horizontal mark/s or line/s, and is still proceeding as squarely as possible across the top of the job too.

As a beginner, you'll most likely find your cut is wandering off the line you marked out. Don't worry about it, it happens to us all. The trick is to spot it early enough (i.e. frequent eye balling), and if going off the vertical then "lean" the whole hacksaw SLIGHTLY in the opposite direction. Make just two or three more strokes, then eye ball again. Keep on until you get your cut back to the vertical, even if it is now a bit further away from the line than you had planned initially - but bad luck if the cut is now into the wanted side of the line and not into the waste side! Just start again with another piece of stock if that dimension is critical.

"Verticality" is the important point to be aiming for, and here the bi-metal blades come into their own as you can (almost) lay the saw flat on it's side before the blade starts to complain - in fact it's odds-on that if you lean the saw sideways much too far, your strokes will be stopped altogether as the blade will simply bind in the kerf (unless that is, you've completed the Charles Atlas Course - "Dear Mr. Atlas, I've done your course, now please send the muscles." I'm sure the under 30's (under 50's?) won't have a clue what I'm on about here!

Never mind, back to business!

Personally, when making angled cuts I prefer setting the work up in the vice so that the cut will still be vertical in relation to the vice and bench, and that's how I was taught. I think it would be quite difficult to cut on an angle to the vice/bench, especially with thicker stock, but if you can make it work for you then I guess it's OK. And of course, if you need a cut which is not at 90 degrees to the main axis of the work piece then you should set the cut line and NOT the main axis at vertical.

As above, wandering off vertical is a common problem, and can ruin a job if you've marked your cut-off line too close to the required final dimension. The only answer is to compensate for this in your marking out, then just keep eyeballing and keep practising with every cut you make until you suddenly find it's "clicked" (as it definitely will).

Also as suggested above, don't be too hard on yourself about a bit of wandering off line, as with a bi-metal blade you'll find it hard to keep dead on to the vertical anyway - that very flexibility that allowed you to save the day when you wandered off line badly during your "beginner cut times" is now conspiring to keep you OFF the straight and narrow! But that's not a reason not to try harder because you'll then "graduate" to using all hard blades, and in comparison to all others, they really are akin to the common "hot knife through butter" saying.

The only other wandering problem you may come across is being a bit off square when the job is eyeballed from above. This is less of a problem as if you've been eyeballing frequently enough, you'll see it and correct for it before any real damage is done. But if required, the correction is simply to adjust your stance a little, and/or to change the angle you're holding the saw in relation to a square line running across the top of the work.

So far I've assumed you're cutting some bar, tube, or strip stock (any metal). But when we get to sheet metal, especially thin sheet, a slightly different technique is called for. Although that "SLOW & STEADY" method is the same, this time, especially when the sheet is large, you'll probably find it much more convenient to lay the job horizontally on the bench.

For a start, with thin sheet material, this helps you keep to the "3 teeth always in contact" rule, because even with a 32 TPI blade you're going to find it impossible to always keep 3 teeth in contact with the job if the sheet is only, say, 1/8th inch (3 mm) thick - trying to cut that vertically it's obviously impossible to keep 3 teeth in contact at all times.

Secondly, especially if you don't want distortions in the sheet (either in the job itself, or on the waste side), clamping the job horizontally onto a bench with an extra support on the waste side is very helpful in reducing distortion to the absolute minimum - I often find my old B&D Workmate good for this. And remember that especially with soft metals like aluminium and copper, it's dead easy to introduce distortion into a sheet, but it's often just about impossible to completely remove unwanted dents and buckles afterwards!

Another point which comes into play, and this also applies when cutting wider/thicker strips and bars in the vice, is that with the job set up in the normal vertical position, a typical hacksaw frame only gives you about a 31/2 inches (90 mm) depth of cut (i.e. the point at which the bottom of the hack saw frame has hit the top of the job, so preventing you cutting any deeper). However the cunning designers thought of this a long, long time ago, and on all hacksaw frames I've ever seen there's a method to allow the blade to be set up horizontally instead of vertically in the frame. I hope the picture shows this clearly.

Photo 10 HS
10 HS-C.jpg


This horizontal blade set up is quite useful when cutting sheet metal as it's now possible to cut sheet of any length - but now you're restricted to strips of only 31/2 inches (90 mm) wide, maximum! Maybe OK for some jobs, but by no means all! But there are other ways to overcome this particular problem which we'll look at shortly.

CONT: PART 2
Last edited by AES on 09 Jan 2018, 23:03, edited 4 times in total.
By AES
#1198845
Now let's look at the blade mounting pin itself, shown above. You'll probably see in the photo that the length of the pin is at least long enough to mount 2 blades side by side. This is a useful trick if for some reason you want an extra-wide cut - as just one example, it's good for forming a slotted screwdriver head in a large diameter screw that you've made or modified. But if doing this I do suggest you choose two blades of the same TPI! - SMILEY!

Hacksaws are by no means restricted to cutting metals. Just like the junior hacksaws discussed above, they're useful tools for cutting a wide range of plastics, bone, plus various boards such as hardboard, MDF, and even wood! And if you've taken my advice and equipped yourself with all three (or four) available TPIs there's lots of scope here. And these bigger frames obviously give you a wider range of sizes and thicknesses of materials to cut than junior hacksaws will allow.

To add even further to the hacksaw's scope, there are some thick-ish wire "Abrafile" blades (see the piece on Files and Filing), which are made with quite coarse "teeth" rather similar to wood rasps. These "wire" blades add further capability to the humble hacksaw and fit the standard 12 inch hacksaw frame well.

Now lubrication. Personally I seldom use it for hand cutting (but very often when drilling or tapping) - after all, hand cutting speeds are normally - or should be! - much slower than drilling speeds, so less heat is generated.

But sometimes when cutting ali a quick drop of WD 40 or paraffin can help, especially if you're getting close to the 3 teeth in contact limit, and if you feel the blade starting to bind in the kerf. Otherwise I MAY use a small drop of light oil such as 3 in 1 or a synthetic drilling and tapping oil if cutting a really thick piece of steel. Generally though I find lubrication unnecessary. But it's up to you, and if lubricating works for you then by all means lubricate.

Finally, just because all hard blades are "dead good", it doesn't necessarily mean that they'll cut ALL metals efficiently. If, when starting the cut with a file as above, and when first using the hacksaw, the file or saw blade tends to "skate" over the surface of the metal (often accompanied by a nasty high-pitched squealing sound) then, as my old instructor used to say, you've got some stock which is "as hard as glass".

If so, try just a few more strokes, and if the noise suddenly reduces, and/or the resistance is suddenly less, then no real problem, you have a piece of "case hardened" stock. Simply continue with standard full length saw strokes and a good hacksaw blade will soon be cutting well. (Explanation: case hardening is a process whereby relatively soft material such as mild steel has been "cooked" while covered in a layer of carbon-rich powder. This creates a "skin" which considerably hardens the outer surface of the metal. But that skin is only very thin so a decent file and/or hacksaw blade soon will penetrate it, quickly getting into the softer "core" of the job).

But if after a few more strokes the file and/or hacksaw blade is still encountering stubborn resistance, and/or if it's still screeching and skating, then you've got a piece of metal which is just about as hard (or even harder) than the teeth of the file or saw blade. Unless you're really desperate there's no point in continuing this way as you'll only wear out the teeth of the blade or file. One best answer here is to use an alternative tool such as an abrasive cut off disc which we'll look at in just a moment.

DETAIL 6. RELATED SAWS:

There are several other saws which belong more or less to the "hacksaw family". Most come under the generic title/s of Pad saw or Keyhole saw and some use either a junior or a full-size hacksaw blade, while others use more specialised blades. The first picture below shows a typical tool aimed mainly at the DIY user I think. Mostly these come with a bi-metal blade, so even with the "support arm" shown, I think many would find this tool difficult to get a decent degree of cut accuracy. Personally I'd rate this as a "useful perhaps/if all else fails" tool. But based on some of the other tools below, personally I doubt that "all else will fail", leading to very little call for this tool!

Photo 11 HS
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The next two pictures show my own Keyhole saw which has its own special-to-type blade. In this case it's an all hard blade of 14 TPI, and is very similar to a hacksaw blade except that it's tapered in width and is about twice the thickness. This extra thickness makes it much stiffer than a standard hacksaw blade. Notice that the blade in this example can be set to a large number of pre-set angles with location slots indexed in the pistol grip handle. Personal rating? Useful on the odd occasion but by no means essential.

Photo 12 HS
12 HS-C.jpg


Photo 13 HS
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Other saws which may be traditionally regarded as woodwork tools can also be pressed into metal cutting service. Fret saws, Coping saws, and Jeweller's (or Piecing) saws all spring to mind. Apart from using fret/scroll saw blades, about which I'll have more to say in a minute, junior hacksaw blades can often be used here, sometimes without modification to either blade or saw frame. The advantage these saws have is an increased available depth of cut compared to standard and junior hacksaw frames, and in some circumstances quite acceptable results can be achieved. See the picture below, which as well as the junior hacksaw blades also shows a short "Abrafile" type blade which can also be successfully pressed into metal cutting service.

Photo 14 HS
14 HS-C.jpg



DETAIL 7. "MECHANIC'S" VICE - SET UP:

I've already discussed that when cutting, for example, thin sheet metal, using the vice may not be the best way to go. But before moving on to other methods of metal cutting using both hand and power tools, it may be worth looking at the business of setting up a metal workers' vice (often called "mechanics' vice"), because that's where a lot of your metal cutting will be done.

First, it's essential for all but the very smallest of vices to be very firmly mounted on a bench (usually with coach bolts), AND also essential that the bench itself is firmly fixed to wall/s and/or to the floor. Unless we're comparing with sawing or planing really large pieces of thick timber, the forces involved in cutting metal are often quite a lot higher than when wood working, so to give yourself a realistic chance of cut accuracy and comfort, a set up which is completely steady under all conditions is a must - for any but the smallest of emergency jobs, a saw horse or Workmate just won't cut it (sorry!).

In terms of the vice itself, I have a cheapo Chinese vice which has served me well for over 20 years and hopefully will continue to do so. Regardless of brand, when buying, choose something which is at least a bit bigger than the size of the biggest job you're likely to handle - the saying about big tools can normally handle little jobs, but little tools can't often handle big jobs is very much applicable in this case.

My own vice has 5 inch (125 mm) wide jaws, and the max opening is a little bigger than that. Being a cheapo it doesn't have a quick release mechanism, which means it's a bit of a faff sometimes, but personally I find QR a nice to have rather than a must have feature. But my vice does have an extra "anvil" casting built in to the vice body, and although that can't be compared with a proper anvil in terms of strength and toughness I do often find it very handy.

Heights (of bench and vice) are very much personal choice, but in my own case, and while suffering with long-standing medical problems affecting my ability to stand upright steadily, I find the oft-quoted "top of the jaws at elbow height" works very well for me.

Being in the cellar, my own bench is firmly fixed to both the concrete wall and concrete floor, so mine was an easy installation. But those with a wooden structure shop probably need to take extra steps to ensure complete stability unless only the smallest of metal working jobs are anticipated. Bearing in mind the forces generated by hand planing though, you've hopefully already got a structure firm enough to take a mechanics' vice - space is another thing altogether though!

To give some general guidance on vice set up I'll quote my own "statistics": I'm approx 6 feet 2 inches tall (1.85 M) and the top of my bench is 38 3/4 inches (99 cm) above the floor. The top of the vice jaws are 441/2 inches (113 cm) above the floor. With that arrangement, and when standing on the thin duckboard arrangement I have in front of the bench, my elbow just rests on top of the vice jaws when bending my lower arm fully upwards until my hand touches my shoulder. Despite my back problems, it's quite comfortable for me to stand at the vice for periods of up to half an hour or so, which is normally quite long enough to do whatever is necessary.

Photo 15 HS
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Finally, note the position of the front face of the REAR vice jaw in relation to the front edge of the bench, as shown in the photo below. The reason is that long work pieces can be held at a sensible height in the vice while allowing the remainder of the job to sit well below the top of the bench - the same idea as for some wood workers' vices.

Photo 16 HS
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DETAIL 8. OTHER USEFUL METAL CUTTING HAND TOOLS:

OK, onwards with metal cutting. Other "non-saw" metal cutting tools include SNIPS AND SHEARS.

These are primarily used for softer sheet metals such as ali and copper and if you haven't seen them before, they're a bit like toughened up paper scissors - PLUS! These do not normally suffer from any depth of cut limitation, but unless you've got a huge grip and the accompanying muscles ("Charles Atlas" again!) these tools are pretty much limited to material thickness of about 1/4 inch (6 mm) or so. The other big disadvantage of just about all standard snips and shears is they invariably result in distortion of the both job itself AND the waste metal.

But if you have an old pair of kitchen scissors to hand (NOT SWMBO's sewing scissors!) these can be very handy for cutting very thin sheet such as shim stock. Used carefully, little or no distortion of either side of the cut results.

There are some other types of snips often named nibblers which use either a small roller or flat "anvil" beside the cutting blade to reduce the distortion problem, but these are quite specialist tools and are not cheap. As this piece is aimed mainly at a woodworker needing to do just a bit of metal work now and then I've ignored them here, but below I do discuss two alternative types of nibbler which I think will be more applicable to the wood worker anticipating just a bit of sheet metal work now and then.

Photo 17 HS
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So next we have the first of the above nibbler alternatives:

Back in the 70's and 80's in UK there was a widely-promoted DIY hand tool called "GOSCUT". I've no idea who made them, and don't know if they're still available. But I have one of the originals, shown below. Although advertised mainly as tools for cutting Formica sheet, I find mine very useful for sheet metal up to about 1/8th inch (3 mm) thick or a perhaps a little more, depending on material and how strong I happen to feel on the day.

The main advantage is that the cutting blade (which seems to be pretty hard BTW, and which is also lightly serrated) actually cuts BETWEEN two fixed flat surfaces. Although fixed during the cut, the spacing between these two surfaces can be adjusted to suit cut radius (by means of the big thumb wheel on the side), a useful feature. And as two separate blades of different widths were supplied, this allows for curved cuts down to quite small radii.

Altogether I find this a pretty good tool for cutting thin sheet metal by hand, and mine has been used quite a lot for thin tinplate, brass, copper, nickel silver and ali sheet. The primary advantage is that because the blade cuts between those two fixed supports ("anvils") there is virtually nil distortion on either side of the sheet. It's also pretty quiet! My tool is still in remarkably good condition for its age, and overall I rate it as a very useful little sheet metal working tool. I also find it useful for cutting other softer sheet materials such as plastics and ply. My advice (assuming they're no longer available new) would be to buy one if you see one at a boot fair or something.

Photo 18 HS
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DETAIL 9. METAL CUTTING "MACHINERY":

HOLE SAWS aren't a complete machine tool of course, but can be conveniently handled here. I'm sure they're familiar to just about everyone, and although mainly a drill-powered tool for wood, MDF, ply, etc, they can have their uses in metal cutting too - primarily for cutting sheet metal. The two main provisos are that you use the finest blade (i.e. highest number of teeth) you can find, AND that you keep the drill rpm as low as it will go. As noted above, bi-metal hole saw blades are freely available these days, but personally as I have other methods of cutting large diameter holes in sheet metal I've never tried these. Being formed into a pretty rigid circular form I imagine they're pretty good. Lubrication (light oil, or paraffin for ali) MAY be necessary, depending on how low the rpm can be set on the drill you're using.

ABRASIVE CUT OFF DISCS aren't really machinery either, but it's also convenient to mention them here as another convenient and quite useful method for cutting metals, especially hard/tough metals in thick wire, bar, tube, and flat formats. Although a good all hard hacksaw blade will work for most such metals, a cut off disc can be very useful for such metals in the larger sizes, or if the material is harder than the saw blade.

Capabilities range according to size and driving method, starting from the small Dremel/Proxxon etc, "mini drill" sizes. For example, the discs for my quite new Dremel "Speed Clic" system are about 11/2 inches (38 mm) diameter and usually 1.3 mm thick, although for their older screw-type mandrels (also shown), Dremel metal cutting discs are available in thickness up to 2.5 mm and up to just over 11/2 inches (40 mm) diameters. And I believe the Proxxon series of drills, plus their special "long neck" angle grinder will all take discs up to 17/8 inches (50 mm) diameter.

These, and the angle grinder discs mentioned below, especially come into their own for cutting hardened tool steels, and also, if the need arises, harder and tougher sheet like stainless and titanium, though as noted before, a good all-hard hacksaw blade will often do the job.

Photo 19 HS
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Abrasive cut off discs for use in angle grinders (shown above, top row) are available in the standard angle grinder sizes, namely from 41/2 inch (115 mm) diameters up through 125 mm, 130 mm, 7 inch (180 mm), and 9 inch (230 mm) diameters. In fact such discs are standard accessories for their respective machines. Some of my own 5 inch (125 mm) discs are shown in Photo 19.

A word of caution here though - as far as I know, although angle grinder discs made from various steels (and tipped with carbide, etc, accord to use) are available for cutting stone, concrete, ceramic tiles, etc, the ONLY discs I've ever seen which are good for CUTTING OFF metals are the mesh-reinforced thin abrasive discs. But all the angle grinder disc variations I've seen are clearly marked with their intended purpose, (i.e. either for grinding edges such as welds, OR for cutting-off, but NOT both). So in practice no problems should arise. But when buying do be watchful and read the markings carefully (on some discs it's not wording in English but instead, those little diagrams/icons which personally I find do sometimes need "reading" at least twice before I'm quite sure)!

AND when cutting metals this way do take some care not to allow the disc to flex side to side too much, especially if you feel the disc starting to jam in the kerf.

The main disadvantage with cutting metals with abrasive discs is obviously the high noise level generated, PLUS the shower of hot sparks which spray out just about everywhere. These sparks are actually a mix of the metal being cut plus the abrasive material the disc is made from. These sparks can be hot enough to start a fire in wood shavings, saw dust, or oily rags, AND are very detrimental to any important metal surfaces they may accidentally collect on - lathe beds and similar cast iron surfaces are particularly susceptible to damage from such highly abrasive dust.

Accurate cutting with discs is sometimes quite difficult, although there are special angle grinder stands available (and plans for self-build versions on the internet). These clamp the angle grinder (or mini drill) in a frame so that the resulting tool looks and acts like a chop saw for wood - some even have adjustable angle settings on them, making them similar in action to a SCMS, though usually without the sliding component.

I use the small size cut off discs quite a lot free hand (Dremel-size mainly), and very occasionally, a cut off disc in an angle grinder, also free hand. As I don't have a chop saw-type angle grinder holder I can't comment on those any further, but I'd guess these find most use in metal fabrication shops and such like, probably where a lot of welding is also done. So they're probably not the sort of gear that the average woodworking shop will have handy.

I've never used any sort of lubrication when cutting metal with abrasive discs and imagine that this could be dangerous from the fire hazard viewpoint. No doubt members will correct this if their experience is otherwise.

When cutting thicker and harder metals though (AND especially fine sections such as piano wire), it IS important to make several light, shallow cuts rather than cutting off in one go. That's assuming the metal being cut has been heat treated, and that it's necessary to retain the same hardness/toughness properties after cutting - cutting off thicker sections in one go can easily lead to over heating of the job with the resultant loss of temper (not to mention the loss of your own too)!

CONT. PART 3

AES

IMPORTANT NOTE: IN A NEW POST JUST AFTER THE END OF THIS COMPLETE POST ("Part 4"), MEMBER graduate-owner HAS MADE SOME VERY IMPORTANT SAFETY POINTS ABOUT CUT OFF DISCS WHICH I DID NOT INCLUDE IN THE SECTION ON CUT OFF DISCS (and which I should have done, sorry). PLEASE READ HIS POINTS BELOW. TO WHICH I'LL ADD THAT EYE PROTECTION WHEN USING CUT OFF DISCS, EVEN LITTLE DREMEL ONES, IS A 100% MUST. PLEASE BE SAFE: ("lecture" over).

AES
Attachments
20 HS-C.jpg
Last edited by AES on 09 Jan 2018, 15:34, edited 2 times in total.
By AES
#1198867
CONT:

Photo 20 HS
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The above NIBLER is bringing us nearer to "real" metal cutting tools, though it is still just a "plug & play" accessory for electric drills. This can be either battery or mains powered, though I think mains power is to be preferred for this purpose. It's the second good alternative to snips and shears for cutting sheet metal that I mentioned above.

As you can see below, mine came in a natty little foam-fitted metal box which contained the unit itself, a handle (VERY important, as we'll see in a minute), plus a spare anvil and spare cutter. Operation is simple - the second photo below shows the hexagonal drive shaft (hardened by the way), chucked into a 3 jaw drill chuck (any capacity of at least a quarter inch (6.75 mm) will do. The nibbler handle screws onto the main body (onto whichever anvil you decide not to use), and then the whole assembly, chucked into the drill, is mounted on a suitable horizontal drill holder fixed to the bench, as shown in Photos 23 & 24.

Photo 21 HS
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As you can see below, the machine is set up as a static fixture, so you bring the job to the machine. The importance of the handle is now clear - unless held still, the whole machine will rotate on the front of the drill, so as noted below, a "third hand" (helper) is very useful here, especially if the sheet to be cut is sizeable. For this reason I've never tried bringing the combined drill/nibbler to the job, though I suppose you could try that if a helper is around.

Photo 22 HS
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In static use the sheet to be cut is fed into the cutting "mouth", having suitably marked the sheet beforehand of course. My own experience is that unless it's a VERY hard material, this little machine will cut anything that fits into the cutting mouth, although the official spec that came in the box states that it will handle up to 1.2 mm steel, which is a whisker over 3/64 inch for those of us who still think mainly Imperial. In fact I recently cut some heat-treated (i.e. toughened) ali aircraft skin of just over 2 mm thickness and it handled that job without protest, though it is advisable to set the drill at the slowest possible speed and keep the feed rate down (although the spec states the max drill speed for cutting as 3,000 rpm).

The advantages are immediately clear I hope - NO restrictions on the size of the sheet to be cut (if you can hold it you can cut it), and considerably less manual input is required than with any hand saw, snips, shears, manual nibblers, and the above-mentioned Goscut. Also, like the Goscut, this little machine will NOT distort either the waste or the good side of the cut, although a little care in marking out is needed as the kerf is 3 mm wide.

The two disadvantages are that in use it makes a helluva racket (of course, the sheet being cut acts as a sounding board, amplifying the row), AND the off cuts (quite small crescents of metal which are pretty sharp) get EVERYWHERE, including sticking fast to the soles of your shoes! This will undoubtedly make you unpopular with household authorities unless you take good care to clear the soles of your shoes before entering the house.

Mine cost me about the equivalent of about 25 quid at a stall at a German model engineering show around 10 years ago, and from time to time I've seen them around in other places too. I also saw on line that a very similar-looking tool is available from Axminster Tools, though these days no doubt at a higher price.

As already mentioned, holding both the job itself steady while guiding it through the machine becomes a one-handed job because the handle of the nibbler MUST be held steady all the while the drill is running. A second person is a definite help here, especially if the job is larger than the fairly narrow sheet of copper I've shown in the (mocked-up) picture.

Photo 23 HS
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But for someone contemplating more than just the one-off sheet metal job personally I would recommend this little tool, PROVIDING your jobs fit the roughly 2 mm max cut capability, and if you (and yours!) can live with the noise. Remember also to make arrangements to catch at least most of the off cuts somehow (a large damp cloth perhaps)?

DETAIL 10. JIGSAWS & "SABRE SAWS"

Now we start off with "real" machines at last, but I don't propose to show a picture of a JIGSAW here because I'm sure we all know what they look like!

However it is worth pointing out that there is a huge range of jigsaw blades on the market, offered by the various machine manufacturers themselves and by various after-market suppliers. My own experience is that as with so many other things, you really do get what you pay for, and personally I've always been happy with the various offerings from Bosch and Makita - not the cheapest, but long-lasting and with a range big enough to cover just about all materials from wood through metals and plastics.

Photo 24 HS
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Personally I use a cheapo jig saw, but as is so often the case with many other types of saw, it's the blade you fit that really count in getting the best results.

When selecting the blade to be used, remember the 3 teeth in contact rule if cutting thin stock, keep both feed rate and cutting speed down and use lubrication for thicker and harder stock. Having said all that however, personally I wouldn't try even a powerful jig saw for cutting, say, 2 inch thick metal because when used properly, an all-hard blade in a hand-held hacksaw will produce much quicker and more accurate results.

But for cutting thin sheet the jigsaw has the advantage that both sides of the cut are supported, reducing any buckling or distortion of the job to the minimum.

Like other power tools though, noise could be a problem, especially with large pieces of thin sheet, where like the Nibbler, the material again amplifies machine and cutting noises considerably.

But as a jig saw of some sort is most likely to be already available in just about every wood hobby shop this is a good standby for just about any odd sheet metal cutting jobs if you really don't fancy the hacksaw. Photo 24 shows some typical jigsaw blades for metal cutting, although those shown are by no means the finest available if you search around (I tend to use the little nibbler shown previously for most of my sheet metal cutting jobs these days, so seldom use a jigsaw for metal unless it's to cut a huge circle or something similar).

DETAIL 11. OTHER POWER HAND SAWS:

Being definitely "a professional and highly devout coward" I've always avoided chainsaws (even the little electrical ones!) so when I needed to cut some thicker tree branches in the garden I bought a B&D saw called "Scorpion", shown below.

Photo 25 HS
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For the job that I bought it for it's "OK for it's - quite low - price", but I was surprised that as well as two separate blades for rough wood cutting, it also came with the metal cutting blade shown below:

Photo 26 HS
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I tried this out purely for interest and I guess that if you ran into a nail when cutting a fence post or something, this blade would do the trick. But personally I can't see either this saw or the above metal cutting blade being suitable if any degree of metal cutting accuracy is called for.

On the other hand I have seen similar-looking (but more expensive!) tools like the example below, and I imagine that with the right blade it could earn it's place in a on-site tool kit for rebar cutting, shuttering dismantling, plumbing, or similar. But again, as a precision cutting tool I have my doubts, though if any members would care to correct this view based on their own experience I'll be happy to be corrected. I also think it doubtful that such a tool would find a place in the average woody shop.

Photo 27 HS
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DETAIL 12. SCROLL SAWS

Getting back to the point again, I wouldn't be surprised to hear that quite a few wood shops have a powered scroll saw somewhere to hand (that's the common American name - we say "fretsaw" in English). So I'd just like to point out that if you do have such a machine, don't forget that blades used in the jeweller's/piercing saw and fret saw frames, as shown above (Photo 14) will also work very well in a powered scroll saw. Actually, you'll probably be surprised at the vast range of metal cutting blades available from all the blade manufacturers, and below, just as an example, I've included a table of just some of the metal cutting blades available from Pegas.

TABLE 28 HS
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Note that the table clearly shows that these pin less blades (ranging from 28 to 59 TPI) can be used in both hand frames and powered saws; also, in the lower part of the table they offer blades for junior hack saws and similar hand frames with a choice of either 15 or 32 TPI.

I've chosen Pegas blades as an example here because I use them quite a lot and find them very good, not "just because they're made in Switzerland"! It's worth noting that Axminster Tools are the UK distributors for Pegas, so you should be able to order from them. The above table is merely a sample of the very wide range of blades Pegas produce, and if you want more details, the web site linked below will allow you to down load a complete set of tables for a vast range of blades direct:

http://www.scies.ch/download-area.html

But before I'm accused of being partisan, there are other blade manufacturers/sellers including Flying Dutchman, Hegner, Hobbies, and Niqa amongst others that you could try.

DETAIL 13. BAND SAWS:

Before we get on to "proper" metal working tools we should also quickly consider the BAND SAW as a potential metal cutting tool - a band saw is, after all likely to be found in many a wood worker's shop.

My own is a small bench top model and is only single speed, but I've seen that larger floor standing machines often have 2 speeds, with the lowest speed being suggested as suitable for cutting metal. With the permission of Mr. Ian John, owner of Tuffsaws in UK (member of this Forum) I quote here a part of what he has to say on his web site about cutting metal on a band saw designed primarily for cutting wood:

QUOTE:
When cutting metal on a band saw the two important factors are the cutting speed and the tooth pitch.

A lot of wood cutting band saws come with 2 speeds and the slower speed is sometimes listed as being for metal cutting - this is sort of true as the slower speed can be used for non ferrous metals (brass, aluminium etc) but is no good for ferrous metal (mild, stainless steel etc).

If the cutting speed is too fast then this will put too much heat into the teeth of the blade and will either cause them to go blunt really fast or the teeth will strip off the blade completely.

Generally the harder the steel, the slower the cutting speed and the following speeds give a rough guide:

Aluminium: - 150 – 1000m/min
Mild Steel: - 50 – 120m/min
Stainless Steel: - 20 – 75m/min

There can be a wide range with the speeds as the quality and thickness of the steel, whether it’s solid or tubed will all make a difference.
UNQUOTE:

I've never tried to use my own little band saw for metal cutting, but a quick check of various online specs show that there are VERY few (if any) wood-cutting band saws which will allow speeds as low as those Ian John quotes above - typical metal cutting speeds which can, incidentally, be verified from just about every metal working data source.

In addition, as Ian's web site goes on to mention, the question of lubrication is a major consideration - heat build up MUST be kept to the minimum possible. No wood-cutting band saws that I've seen make any provision for lubrication, leaving the user to try to brush or can drip-feed lubricant onto the cut. Particularly with the harder ferrous metals lubrication is VERY important, and the idea of trying to drip-feed some sort of liquid onto the cut while the machine is actually running sounds pretty hairy to me!

Not only that, and assuming that sooner or later I'd want to cut some wood again, I would NOT like to try to clean up the blade and the machine after metal cutting lubricant has sprayed all over the place, even if my hand-feed lubrication efforts had not resulted in the loss of a digit or two!

In short, although it may be tempting at first sight, my strong recommendation if you're tempted to try cutting metal on your wood-cutting band saw is simply "forget it"! As just an occasional metal cutter, there are already plenty of better options, some detailed above.

Below I've added an internet picture of a typical metal-cutting band saw, the sort quite often to be found in metal fabrication shops. If you look closely you'll see quite a few differences between whatever wood-cutting band saw you have and the machine shown - not the least being an integral lubrication system.

By the way, Tuffsaws do sell made to measure metal cutting band saw blades, so if you have access to a suitable machine, based on the excellent reputation for wood-cutting blades that Tuffsaws enjoy, a Tuffsaws metal cutting blade would be a very good choice I think (usual disclaimers).

http://www.tuffsaws.co.uk/

Photo 29 HS
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CONT. PART 4

AES
By AES
#1198873
DETAIL 14. POWER HACK SAWS:

Photo 30 HS
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Again I've added an internet picture of the type of machine often to be found in general machine shops and metal fabricators - unlikely to be found in the average woody shop I guess! So why include it here?

Because earlier on I mentioned the (apparent) lack of availability of 14 TPI blades for hand hacksaws and went on to suggest that for really hard metals, the soft-backed diamond/carbide encrusted hack saw blade was sometimes a useful substitute. But with a bit of modification to a suitable hacksaw frame, there's an even better alternative, as shown below:

Photo 31 HS
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This is a typical blade for a power hacksaw like that shown above. It's a 12 inch (300 mm) long all hard blade with 10 TPI, but interestingly, the other dimensions are 1 inch (25 mm) wide, and 0.050 inches (1.25 mm) thick. In other words, this blade is the same length but about double the width and twice the thickness of a hand hacksaw blade. The only other difference is the diameter of the pin holes - on the hand hacksaw blade the pin hole is approx 4.5 mm diameter, while the power blade pin hole is approx 8.3 mm diameter.

Power hacksaw blades are available in both bi-metal and all hard versions (and in various lengths too) but obviously, for a hand hacksaw frame, we'll need the 12 inch (300 mm) long versions. Typically these are either in the above 1 inch (25 mm) or 11/4 inch (30 mm) widths, with a choice of either 6, 10, or 14 TPIs in both widths. Although the costs are pretty high, just one will cover just about every need, and should last a lifetime. As shown I have a 10 TPI power blade and it works very well indeed for me. The main manufacturers are those named in the last section below.

So by simple modification to the 2 locating pins on a hand hacksaw frame (choose a single-sided holder type, not the slotted type shown in Photo 14 above - or simply widen the slot if yours are like mine), we have a hand hacksaw which, being twice the thickness and width of a standard blade, will not flex very much at all. Furthermore it's also just about unbreakable (unless you're REALLY trying!), and as it's made of HSS it's hard enough to cut almost any metal, and with 10 TPI, it's ideal for cutting the thick sections of stock with minimum of effort!

If such a power hacksaw blade is added to our existing armoury of three (or four?) "standard TPI" all hard or bi-metal blades, along with the possible addition of a diamond/hard metal-coated blade, we end up with a cheap and simple hand tool capable of cutting just about any metal the woodworker's world is likely to send his or her way. AND, if operated in the "correct" way described in detail above, all cuts will be accurate, achieved with minimum physical effort, and in the shortest possible time. What more could youe possibly ask for?



I think that by now I've covered all the likely options for the average wood shop just cutting some metal now and then. Of course there are many other much more specialised metal cutting machines, including power shears and guillotines, water jet, flame, laser, any and all of which can be CNC controlled. But in my view all these are outside the scope of this piece

But if you're faced with needing some specialist metal working done, especially in batch quantities, don't forget the internet and local adverts, where you'll often find jobbing machine shops and fabricators with the necessary specialist equipment willing to take on such work on a sub-contract basis.

DETAIL 15. HACKSAW BLADE MANUFACTURERS:

Here's my personal "Top Three" hacksaw blade manufacturers, plus a few other possibilities:

James A. Neil "Eclipse" brand (is/was from UK) - Excellent, especially their all hard blades (IF you can still find them);

Sandvik "Sandflex" (maybe "masquerading" under the brand names of "Bahco" or "Oberg", depending on how the "marketing flower arrangers" are feeling this year - from Sweden) - Good;

Starrett (from USA) - Excellent, especially their all hard blades (IF you can still find them).

In addition I've also recently found some non bi-metal blades in my local DIY emporium. These are painted dark blue overall and marked "Lux Tools". This is a German company and part of the Obi Group (Obi is a German national chain of large DIY stores). Their web site doesn't make it clear if they themselves are the manufacturer or simply a distributor (I suspect primarily the latter), but as well as being available in the Obi DIY supermarkets they're freely available elsewhere in mainland Europe too, though sorry, I'm not sure about UK availability.

I've had a few of the Lux power and hand tools in the past and they're about mid-price with acceptable quality - not usually just cheapo rubbish. I'm not sure if the hacksaw blades I found are all hard but they're definitely not bi-metal. And to refute my earlier statement about Imperial measurements, these blades are marked "300 mm x 7 teeth/cm"! They fit my hacksaws OK, and from measuring fairly carefully they seem to be about 18 TPI (which equates roughly to their stated 7 teeth per cm). From a first try they seem to be quite OK and after two small jobs they haven't started to blunt yet, so perhaps they'll be (almost) as good as my favoured Eclipse and Starrett all hard blades?

I'm sure there must be other good brands (?), but although a quick Google for "manufacturers" showed me, for example, 18 companies in Germany and 3 in Switzerland, none were names that I'd heard of before and a quick look at some of their web sites suggested they're either dealers or importers of other manufacturers' stuff. In addition, Google showed LOADS of Chinese and Indian manufacturers - no big surprises there then!

I'm sure that there must be more manufacturers of good, high quality blades, but if so, I don't know of any beyond the "Big 3" above, sorry. But if a Forum member wants to add manufacturers' names based on own-usage experience it would be very useful - what we'll all do if all 3 of the above decide to give up blade manufacture I just dunno!



I do hope this lengthy piece helps at least some members who are maybe a bit anxious about metal bashing to now start to think of cutting metal as a job in which they can be pretty confident of a successful outcome, instead of just feeling it's a boring, hit and miss, physically tiring drudge. As a further incentive to that end here's a final observation:

Recently I bought the book "Making Woodwork Aids & Devices" by Robert Wearing from a member here. Being a woodwork newbie I hadn't heard of it before and found it very informative as well as an interesting and useful read. A number of the ideas shown were definitely new to me and some will find a place in my own shop.

I'm sure the "woody experts" here will already know of this book (or of something similar), but what interested me was seeing how many of the various jigs and devices shown need not only woodworking skills (of course) but need at least some basic metal working skills too. In short, the sort of basic metal working skills discussed here and in my previous "Files and Filing" piece.

So if my posts help you to tackle a bit of metal bashing with more confidence then I'll be well pleased.

Wishing you a Happy and Healthy (and a metal bashing) New Year.

AES


PS:

Sorry for all the confusion and multi parts above. CHJ did kindly take the time to explain all this "joined up" posting to me, and I though I understood it - but clearly I didn't! (hammer)

Hope it's helpful and readable anyway, cheers.

Edit for a later P.S. Looks like some kind Mod (CHJ??) has joined "my bits" up altogether. Anyway, whoever it was, thanks a lot.

AES
By NazNomad
#1198994
Great post, and thanks for taking the time to do it.

- adding washers for more tension. Used that trick on my coping saw for years but never thought to do it with a hacksaw.
- using woodworking style coping/fret saws is great, but still install the metal cutting blade teeth-backwards to overcome frame flex and lack of beam strength in the blades.
- holding and using a hacksaw properly. Takes me back (cough) years to College when I was shown that and have never forgotten it. I suppose it's like any tool, using it properly makes the job so much easier.


I've been postponing a hacksaw blade purchase for months because I can never decide on a good balance between quality and 'allowed budget'. Any recommendations?
By TFrench
#1199005
I hate junior hacksaws with a passion. Yet to see anything ever cut to a decent standard with one!

Naz, we've just got some RECA blades at work that are progressive - fine teeth at the front for getting started then slightly coarser in the middle for speed. Really impressed with them.

Edited to add:
1mm slitting discs for a 4" angle grinder. These things are fantastic. Very neat cuts, little heat. I use them all the time and for most basic fabrication work they replace a hacksaw for me. Only downside is sparks: be VERY careful where they go in a woodwork workshop!

If you do a lot of sheet metalwork in thin gauge, we've just invested in a couple of these at work:
http://www.bosch-professional.com/om/en/cordless-metal-shear-gsc-10-8-v-li-226567-0601926175.html
Absolute game changer. Incredibly controllable and neat, very little distortion on the workpiece. Overkill for DIY'ers, but it may help somebody!
Last edited by TFrench on 08 Jan 2018, 23:16, edited 1 time in total.
By NazNomad
#1199007
TFrench wrote:Naz, we've just got some RECA blades at work that are progressive - fine teeth at the front for getting started then slightly coarser in the middle for speed.


Cheers for that. My 'go to' junior hacksaw is my Eclipse one. It's really comfortable to use and the tension is way better than those bent-rod jobbies.

Image
By AES
#1199032
@NazNomad. Thanks for your thanks Naz.

Re blade choice, as per my post (last page), if you can use a hacksaw without breaking an all-hard blade, then personally, I'd go for all-hard every time. It's just my feeling, but I've always preferred Eclipse, followed by Starrett (their "red stripe"), followed by Sandvik ("Bahco") or whatever they call them these days. Just my own feeling.

But if you've got a lot of big stuff to cut, why not a power hacksaw blade? (same manufacturers' order as above). Only problem is, I saw that Starrett, for example, wanted over 200 USD for a dozen - FAR too many for a "hobbyist", they'd last a life time+! But if you could find a retailer who'd sell them in singles then I'd go for that (I'm lucky, I have 3 x 10 TPI Sandvik power machine blades).

I suppose I could sell you one if you really want one though - no idea how much though (offer?), and postage from here, even for a single blade, would probably be a bit silly (our PO IS silly).

HTH

AES
By AES
#1199037
@TFrench.

Thanks for the comments. Those Bosch nibbler machines look great, I WANT one!!!! (But NO chance of that, with that little attachment Nibbler I showed, I'm quite well set up, and anyway, SWMBO will go mad if even MORE tools come into the house - even creeping in via the back door!)

I'm not a fan of junior hacksaws either, but Naz's looks good. I inherited my "Little Marvel" from my Dad.

Have you tried increasing the tension with a thick washer? Also, have you tried the Pegas junior hacksaw blades (should be able to order from Axi)? But in a general way, I do agree with you, juniors are a bit of a pain, but do have their place (sometimes!).

Cheers

AES

Edit for P.S. I've never heard of RECA blades, thanks. Where do they come from? And what's with the "progressive teeth" business please?

AES
By NazNomad
#1199038
AES wrote:I've never heard of RECA blades, thanks. Where do they come from? And what's with the "progressive teeth" business please?



I couldn't find info on RECA blades, but I have found some from another company.

Seems they change from 32 -24 -18 tpi along the length of the blade. So you can start fine and rip through once you get going.
By dickm
#1199053
Just one word of warning about nibblers, having spent what seemed like a lot of money for a mains version of the Bosch shown by TFrench (but in the days when I did some Volvo restoration, it earned its keep in a very short time). Those little crescents of metal that come out with each nibble are the very devil to clear up, and have a habit of attaching to shoe soles, bike tyres, even dogs' paws with unpleasant results. If possible, use the nibbler either somewhere where the niblets won't matter, or on a dead smooth surface so they can be picked up cleanly.
User avatar
By CHJ
#1199062
dickm wrote:....Those little crescents of metal that come out with each nibble are the very devil to clear up, and have a habit of attaching to shoe soles, bike tyres, even dogs' paws with unpleasant results. ..


When working with ferous material I have a large surplus 'Magnatron Magnet' in the vacinity that collects the debris.
For hacksaws or grinders, old Computer Hard Disc magnets are good for containment, have three around the base of my Pro Edge for instance.
By AES
#1199063
Thanks for the comment about those little nibbler crescents dickm. I did point it out in my post (1st time I used mine I ended up unknowingly treading loads up into the house on the soles of my shoes. I weren't 'arf popular with SWMBO!), but it's good to have someone else reinforce that message.

CHJ's "gert big" magnet is a good idea - but as he says, unless you're cutting sheet ali of course :D

I'll look up those RECA blades, thanks Naz. Never heard of "vari teeth" blades before. A bit like varifocal specs I guess.

Thanks for the feed back folks, glad the post is useful.

AES
By graduate_owner
#1199104
Again an excellent reference for beginners and regulars alike, well done.
Can I add a few comments of my own? Firstly regarding angle grinder discs, where you say you should use one type for grinding and one for cutting - readers might be tempted to do so unless they know the reason, which is -

Grinding discs are thick so you can use the flat surface as well as the edge. But being thick, if you try to cut metal with them you will probably overload your grinder, and will definitely take a lot longer because of the wide 'kerf'.

Cutting discs are thin, some are available at just 1mm thick. These are just brilliant for cutting because being so thin they seem cut easily and quickly. I thought they would wear away in no time but indeed they do last. But if you use these, or the thicker (about 2mm) discs for grinding on their flat surface then you would seriously weaken them and they could disintegrate.

My second point is regarding 9" grinders. These are real workhorses but are pretty powerful and could give you a nasty surprise if you accidentally twist the disc, and hence jam it in the material being cut. If this happens then the grinder can easily be wrenched from your grip with potentially serious injury if the spinning disc touches you, although they operate on a trigger switch which has to be held down to switch on. Still nasty until the disc stops. To help avoid this you can buy a nut with built in clutch which is supposed to slip if the disc jams. I have bought one - under £10 but I don't know how well it works as I haven't yet jammed the disc ( and I really don't want to do it purposely to try it out)

Finally, the Goscut. I bought one years ago and I still have the cardboard packaging. I believe it says made by Eclipse.

That's it.

K
By TFrench
#1199125
dickm wrote:Just one word of warning about nibblers, having spent what seemed like a lot of money for a mains version of the Bosch shown by TFrench (but in the days when I did some Volvo restoration, it earned its keep in a very short time). Those little crescents of metal that come out with each nibble are the very devil to clear up, and have a habit of attaching to shoe soles, bike tyres, even dogs' paws with unpleasant results. If possible, use the nibbler either somewhere where the niblets won't matter, or on a dead smooth surface so they can be picked up cleanly.


The beauty of that nibbler is that it works like scissors - there's no little bits punched out. We do a lot of our work in food factories and they'd go mental if we used one of the punch style machines in there!

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